The present invention relates to a device for reducing discharge of noxious substances emitted from an internal combustion engine.
Marine diesel engines emit exhaust gases and utilize a closed circuit cooling system which uses once through sea water to take away the heat of the engine. The thus heated sea water is introduced as a stream into engine exhaust piping, which is downstream of the engine. This stream of heated sea water is discharged together with a stream of hot exhaust gases which contain noxious fumes. The two streams remain essentially unmixed, retaining their own respective temperatures while flowing through the engine exhaust piping.
Vessels with marine diesel engines share a common problem in that the noxious fumes from the exhaust emissions reach people aboard and in the vicinity of the vessel; this problem is most pronounced when wind currents carry the exhaust fumes back onto the deck at start up or when the vessel docks or moves about slowly. In addition to being unpleasant, noxious fumes contain solid and liquid particulates and volatile hydrocarbons from partially combusted diesel oil fuel. Fortunately, when the marine diesel engine is under significant load, such as when the vessel is travelling at a relatively rapid speed, the engine runs hotter and the combustion of the fuel is more complete. The exhaust produced is less obnoxious and, because the vessel is moving at a more rapid rate, the fumes are less likely to be troublesome to the people on board.